Drafting instrument.



W. O. POCKLINGTON.

DRAPTING INSTRUMENT.

APPLICATION FILED 00110, 1910. RENEWED NOV. 9, 1911.

Patented July 2, 1912.

2 SHEETS-SHEET 1.

W. C. PUCKLIN DRAFTING INSTRUMER APPLICATION FILED OCT.10,1910. RENEWED NOV 9, 1911. 1,031 665 Patented July .2,1L912v BEETS STATES rn rnnir OFFICE.

WELLIAM C. BOCKLINGTON, EVANSTON, ILLINOIS,

DRAFTING- INSTRUMENT.

Specification of Letters Patent.

' PutentedJuly%'1912.

' Application flied Gumbel; 1Q.- 1910, Serial No. 5.56.252. Renewed November 9 1911. Serial No 659,423.

/ a resident at the ('ity ot 'E 'u-uston, county Qther objet'ts will appear hereinafter.

\Vith these objectsin view my in \"ention eo rists in a din fti'ugdeviee characterized- .ned and ineertain details of as mYO men construction and zu-i'rrrtgei-i eiits-ot parts. all

I as ivill li'e hereinafter more fully described -andparticularly pointedout in the append.

.n\ -=ei it-io.n willhe more readily-understood by reference to the aeeompanying drinrings forming apart of this-specification and inivhieh;

Figure 1 is a top. plan View of a dravving beard and a T sluare applied thereto in vhi'ehis en-rhedie the preferred form of my invention, Fig. 2 is a side elevation thereof,.\\-'ith parts broken away. Fig. 3 is an enlarged fragnuentary top plan view ofthe head-of the T square. and portion of'the- (-onstrnctimi adjacent thereto, and Fig. l. is a section taken substantially on line of Fig. 3.

The preferred form of my invention as illustrated in the (lIl1\VlI\ S '()lTTPl'lS8S a drawing .tzrble consist ng o? thfetop 1 and the supporting legs 2. To the top 1 at the peripheries therenf' are secured straps or rails. 3'forming a'rectangular recess 4 for the snug receptiono'f the drawing board 5 which is remorably arranged therein, said drawing board being preferably of a thiekness slightly lessv than that "of said rails so that, when the blade of a T square is drawn over the table said blade will not Contact the upper suirfaee of said board but will rest and slide upon rails 3- at the opposite sides of the table.

Rigidly secured as by serewsor by other suitable securing devices 6. to one of the citizen the United States. and

side rails 23 at the extremities thereot are outwardly projecting brackets 7 provided in their outer ends withperforations 8 nhieh serve as bearings for the reduced extremities of an oscillatory bar 9, the latter being preferably rectangular in cross section.

Arranged upon'the drawing table is a T' square comprising the head 10 and the blade l1. Said head is preferably formed of metal, and to the under side of said head at the extremities thereof are provided channel rollers 12 adapted to rotate upon and to snugly reeeive the inner edge of the bar 9 Fri-med integrally with and outwardly projerting from the head 10 midway between the extremities thereof is an arm 13. Ar" ranged upon the under side ofsaid arm 13 is a substantially U-shaped bearingmember or yeke H the latter being secured to said arm for adjustment in a line transversely of the bar 9 by means of scre'ns 15 which pass through elongated slots 16 provided in said arm, the lower endsof said screws heing threaded into said bearing member. As seen, the said screws are provided with knurled heads so that manual rotation thereof'in order to effect adjustment of said bearing member 1-1- may be readily effected.

In order to elfectready inward movement or :uljustment of said bearing member a feeding sereu 17 is provided, the letter be ing threaded in o a In; 18 formed at; the outer extremity of the arm 13, the inner extremity of said sereiv abutting the outer most of the screws 15. Such pro ision evidently atl'onls means for effecting ready in \vard movement or adjustment of said heat ing member and also serves pm-sure stop to prevent any outward Ir vezmthereof after adjustment. )hlounted .ir 2 7 bearing member is a. ehannel roller l lar to the rollers 12, the same restirg it gagement with the outer edge of t. or the edge of the latter opposite. in. engaged by the rollers 12." \Vith the arrangement d seen that the head 1C bar 9 agaiz latter except m By reason of -s adjustmentalien .J. bearing member 9 as above ole- 1.. rollers may at all times'be held gagement with the 9 so any lost motion occasioned by The rearward end of the blade 1-; is rigidly secured to a block QO the upper side 0 lengit which is recessed as at 21 to snugly receive said end of said blade, a screw 22 servin to lock said blade thereto. The rearwar end of said blade is pi otally secured to thehcad 10 by means of a screw 23 which extends loosely through said head, the lower end of said screw being threaded into said block. The arrangement is such that b loosening said screw said block and blade will be free for angular adjustment relative to thehead 10. Positive locking of said block and blade in position of adjustment relative to the head 10 is effected primarily through the medium of a screw 24 which projects through an arcual slot 25 provided in said head, the lower end of said screw being threaded into said block. In order to facilitate ready rotation of the screws 23 and 24 in the adjustment of the blade 11 the same are preferably provided with en larged knurled heads as indicated. Secured 'as by screws 26 to the blade 11 centrally thereof and adjacent the head 10 is a finger or pointer 27 which is adapted to coiiperate with arcual graduations 28 provided upon said head, this provision evidently adapt-' and by reason of the adjustment afforded by the roller 19 lost motion due to wear may be readily taken up and hence the posir tion of the blade of the T square relative to the board constantly maintalned.

W'hile I have shown what I deem to be the preferable form of my drafting device I do not wish to be limited thereto as there might be various changes made in the details of construction and arrangement-s of parts described without departing from the spirit of the .invention as comprehended within the scope of the appended claim.

Having described my invention what I deem as new and desire to secure by Letters Patent is:

In a drafting device, the "combination of a drawing table; an oscillatory bar arranged at one side of said table; a T square head carrying spaced rollers on its under side and contacting with one edge of said bar; a yoke adjustably secured to the under side of said head between said rollers by means of bolts passing through transverse slots in said head; a set screw on said head and contacting with one of said bolts; a roller carried by said yoke and contacting with the other edge of said bar between said aforementioned rollers; and a blade secured-in said head, substantially as described.

In testimony whereof I have signed my nameto this specification in the presence of two subscribing witnesses.

WILLIAM C. POCKIIJINGTON.

Witnesses:

FLoRuNon E. LILLIS, JOSHUA R. H. Form. 

